Solution : https://service.sap.com/sap/support/notes/1603475 (SAP Service marketplace login required)
Key words : 
configuration > miscellaneous > conduct risk analysis, terms business role management, business role management, symptom error occurs, system <system id>, risk management system, performing risk analysis, risk analysis & remediation, prerequisites risk analysis, risk analysis
Related Notes : 
       
| 1548963 | Role is not generated in ERM | 
| 1277326 | Risk analysis failed in ERM | 
| 1265964 | Risk analysis in the ERM does not show any results. |